This document discusses mergers and acquisitions (M&A). It defines key terms related to corporate control and structure. It provides examples of recent large mergers across various industries. It outlines both sensible and dubious rationales for mergers, including economies of scale, filling complementary needs, surplus funds, diversification, and earnings per share manipulation. The document discusses estimating potential economic gains from mergers using discounted cash flow models. It also covers leveraged buyouts, takeover defenses, and methods of acquiring companies like tender offers and proxy contests.